On Wed, 19 Feb 2020 12:09:50 GMT, Arun Joseph <ajos...@openjdk.org> wrote:
> With new bytecode format introduced in Webkit 608.1, the unlinked and linked > bytecodes were replaced by narrow (1-byte operand) and wide (4-byte operand) > bytecodes. These were extended to narrow, wide16 and wide32 bytecodes in > WebKit 609.1. In narrow instructions, each argument of the opcode has a fixed > size of 1-byte. The same applies for wide 16 and wide32 with 2-byte and > 4-byte, respectively. > > In the Low Level Intepreter (LLInt), each opcode has a corresponding ID > assigned for narrow, wide16 and wide32 implementation, and the variable > `numOpcodeIDs` is used to denote the total number of opcodes. The narrow > opcode IDs are mapped from 0 to (`numOpcodeIDs` - 1). The next `numOpcodeIDs` > opcode IDs are mapped to wide16 opcodes, and similarly, the next > `numOpcodeIDs` to wide32 opcodes. The same can be found in > [LowLevelInterpreter.cpp](https://github.com/openjdk/jfx/blob/master/modules/javafx.web/src/main/native/Source/JavaScriptCore/llint/LowLevelInterpreter.cpp#L265) > and also in the autogenerated file `Bytecodes.h`. > > Bug: When `getOpcodeWide(id)` is called in `LLIntData.h`, the value (`id` - > `numOpcodesIDs`) is returned. > > Fix: It's modified to (`id` + `numOpcodesIDs`) in `getOpcodeWide16()` and > (`id` + `numOpcodesIDs`*2) in `getOpcodeWide32()`. Fix looks good. Testing looks good. ------------- Marked as reviewed by kcr (Lead). PR: https://git.openjdk.java.net/jfx/pull/115
